Protective apparatus



Feb 28,' 1933- J. v. BRExsKY 1,899,745

' PROTECTIVE APPARATUS Filed Oct. 20, 1950 V MT 'n Second;

INVENTOR 33 Joh/2 VBI-@1191( y /2 Per femLaaa 20,00 TQRNEY accordingly to devices and Patented-Feb. 2s, 1933 AUNITED STATES PATENT ori-ica JOHN V. BBEIBKY, Ol' PITTSBURGH, PENNSYLVANIA, LSSIGNOB WESTIIGHOUBI ELECTRIC IANUFACTUBING COIPANY, A' CORPORATION 0l' PENNSYLVANIA PROTECTIVE APPARATUS Application Med October 20, 1930. Serial lo. 489,826.

This invention relates to electro-responsive particularly to relays of the induction type.

The theory and manner of operation of induction-disc-type relays is' well known to,

those versed in the art, and the problem of providing suitable time-operation characteristics for such relays has furnished a fertile iield for research and development.

Load apparatus is usually designed to operate, for a limited time, under overload conditions, and relays have been designed provide suitable operating characteristics. o secure apparatus or system protection, whereby limited overloads are permissible in order to take care of transient or small overload conditions, an o rating characteristic is imparted to the re ay such that a period of time will elapse before the relay contacts will close.

'The provisionlof such operation characteristics for alrelay prevents the closure of its contacts until some time interval has elapsed after the energizing current has exceeded a predetermined value. The apparatus or s stem to be protected may, therefore, be maintained in operation during transient or predetermined overload conditions.

In an induction-disc relay having a main energizing winding on one pole and a secondary winding on an adjacent pole, the torque exerted on the relay disc is proportional to the product of the main pole flux times the adjacent pole flux times the sine of the phase angle between them. The present invention embodies a novel means of providing a definite time characteristic for such a relay, oran induction-disc relay of any type. In order to obtain a definite time oi operation, the product of the main pole flux times the adjacent or secondary pole flux times the sine of the angle between them must be maintained submantially constant for the operating range of the relay.

In accordance with the present invention, a torque-compensating means is utilized to predetermine the magnitude of current flow `the resultant torque acting upon the relay of the main energizing winding.

The compensator comprises two windin wound in inductive relation upon a magnetic core, the primary winding thereof being connected in series with a secondary winding of the relay and, therefore energized by a current in roportion to the current energization of t e main winding of the relay. The secondary winding of the relay is wound on the saine pole as the main ener ing winding. Assuming this pole to be tgdzlower pole of the relay, another secondary winding is disposed upon the upper pole of the said relay to cooperate with the main energizing winding to provide a rotating torque for a disc armature. The relay secondary winding is connected in series with the secondary windingof the torque compensator, and the current fiowing through both of the windings is the same.

The torque compensator is adapted to be moved with res ct to the main energizing winding to permit different values of the leakage flux of this winding to link with the torque compensator. The position of the compensator must be such that the leakage lux of the main energizing winding links the secondary winding of the torque compensator to decrease the effective lflux linking that winding. In other words, the primary winding of the torque compensator is energized proportionally to the energization o the main winding of the relay, and the l flux of the main winding is caused to link the secondary winding of the torque Ycompensator in a direction to o the flow of current in that winding. e changing of the amount of flux linkage with the secondary winding causes a corresponding change in also 'the value of current flowing therein, an

winding, since the two windings are connected in series. The current through the relay secondary winding may thus be changed for any given condition by adgustment of the 53 torque compensator, and the altering of the linking leakage-dun provides that the product of the dunes of the relay windings and the sine of the angle between them may be made essentially constant for the operating range or the relay..

The iron circuit of the torque compensator is designed to saturate for predetermined values of current owing in its primary winding, and a constant value of current may, w therefore, be made to vHow in the secondary winding of the torque compensator. From this, it may clearly be seen-that the time-load' curve of a compensated rela7 may be made lineal for predeterminedi va ues of current 2@ energization of the relay.

The invention may best be understood. by referring to the several figures of the drawing, wherein llignrel is a view, in front elevatlon, or a portion of a relay structure.

Fig. 2 is a view, in side elevation, correspending to the arrangement shown in Flg. 1.

Fig. 3 is e, bottom plan view of the arrangement shown in Figs. 1 and 2.

Fig. 4 is a schematic diagram of theelectrical connections of the relay and compensator windings.

Fig. 5 is a detail diagram illustrating a modication which utilizes a torque compensator of a dierent type.

Fig. 6 is a graphical illustration of char# acteristic time-loadV curves of a relay utilizing the present invention.

With more particular reference to Figs. 1, 2 and .3, an induction-disc relayis represented as having a core 11, comprising a plurality of iron laminations, and windings 12 and 13,

associated with lower and upper core portions 14 and 16, respectively. The winding 12 constitutes the main energizing winding of the relay and a. secondary winding, the

two being schematically represented by theV windings 12 and 12' in Fig. 4.

The ux produced by the main energizing winding duced by the secondary windings 13 to eiiect a rotating torque upon a disc armature 15 disposed' between the core portions 14 and 16. 1t may be readily understood that the relay structure, as represented in Fig. 1, 2 and 3, is merely diagrammatic and is to be considered as representative of an induction-disc Vrelay of any type.

According to the present invention, a torque compensator, comprisin an iron circuit 17 and inductively relate windings 18 and 19, is adjustably disposed with respect to the relay-energizing winding 12.

The iron circuit 17 comprlses a plurality of-iron laminations which are secured to- 12 combines with the uxes pfro neueres gather by means oi machine screws 21, and the torque compenmtor, including the inductively related windings 18 and 19, is slidably mounted adjacent to the lower core struct I, m

lower portion of the core 11 by means oi bolts. w 24, extending therethrough, and secured by means of nuts j rlhe supporting member 22 is provided with a Vernier screw 27` which is adapted to turn :freely in its assembled position, as indicated in Figs. 2 and 3. @ne side of the torque compensator is provided with supporting members 28 of L-shape which are adapted to be moved, by the `vernier screw' 27, 'laterally with respect to the supporting member 22 and the core 11. The guide 23 is provided with a slot 29, suitable for guiding the ends of the supporting members 28 re-V mote from the Vernier screw 27.

By turning the vernier screw 27, the torque compensator may be moved laterally with respect to the core 11 and the main relay winding 12. As pointed out hereinbefore, the torque compensator is supported by the members 28 andis positioned by means of the gernier screw 2 and the guiding member Referring to Fig. 4, the main energizing winding 12 is wound upon the lower pole of a relay and is adapted to be energized in accordance with the current flowing in an alternating-current system. A secondary winding 12 is also wound on the lower pole of the core 11 and is serially connected with the primary winding 18 of the torque com-V pensator. r1`he secondary winding 19 of the torque compensator is serially connected with the relay secondary windings 13, and the currents through the said relay current windings is controlled by the amount of current permitted to dow in the secondarywinding of the torque compensator.

Assumingl the instantaneous current lowing in the main relay winding 12 to be in a direction to produce an upward iiux in the low-l er pole of the core 11, a current willbe set up in the secondary winding 12 which is in .a reverse direction with respect to the current owing in the main winding 12. The

current flowing in the secondary windin 12' also ows in t e primary winding 18 o the torque comp7 nsator and generates a ux in the iron core 1 A secondary current is thereby generated in the secondary winding 19 of the torque compensator in a direction to oppose the inducing flux set up by the primary a winding 18, and the current owing in this secondary winding Hows through the. relay secondary windings 13.

Referring again to Fig. 2, the energizing l current owing in the main coil 12 sets up a leakage iux around the coil and the lower pensator 1s movably to the energizing coi that, by placing the ,winding 19 of the torque compensator. vObviously, the positioning of the torque compensator in its extreme right-hand position will permit lthe linkage of the greatest possible'number of lines of leakage flux of the main energizin winding 12with the secondary coil 19 of t e torque compensator. The moving of the torque compensator to its left-hand position, or towards the front of the relay, decreases the effective linkage of the leakage flux of the main energizing winding 12, since the core 11 offers a better return path for the leakage flux than does the iron circuit of the torque compensator. Itmay be seen, therefore, that the movement of the torque compensator to various positions, by means of turnin the vernier screw 27, causes a. predetermineg amount of leakage flux of the main energizing winding 12 to link the torque compensator, depending upon the' degree of energization of the coil 12. v

Assuming the current in the primary wind- Y ing 18 of the torque com nsator to be flowing in a direction-to pr ucea magnetic flux in the iron circuit 17 in a clockwise direction, a current is induced in the secondary winding 19 which tends to oppose the flux roducing it, as in a usual transformer. T e positioning of the torque compensator in the leakage field of the main energizing winding 12 results in this leakage flux so linking the torque compensator as to oppose the magnetic flux set up in the torque compensator by the energization of its primary winding 18. lt follows, therefore, that the more lines of leakage llux which are permitted to link with the torque compensator, the more the current in the secondary winding 19 will be reduced because `of the bucking effect of this flux with respect to the magnetic flux produced by the primar winding 18.

By c anging the value of current flowing in the secondary winding 19, the current flowing in the relay secondary windings 13 is also necessarily changed because these windings are connected in series. Since the torque produced by the lrelay windings 12 and 13 depends upon the value of current flowing therein, any change in the relay secondary current will result in a proportionate change in the relay torque. 00 The iron circuit 17 of the torque compensator is designed to saturate for predetermined values of current flow in the primary winding 18, in order to prevent the flow of current in the secondary winding 19 above a predetermined value. Thus, irrespective of the degree of energization of the main energizing winding 12, the current permitted to flow in the secondary windi 19 of the torque 'compensator and in [the secondary wmdmgs 413 ofthe relay is maint'alnedconstant above a predetermined value of v inding12. In addition to limiting the magn1 tud e of current ilowin in the secondary winding 19 by means of t e saturation of the iron circuit 17, the torque compensator may be moved to rmit the linkage of differentvalues of. lea age flux of the main energizmg wlndmg 12, thereby rovidin a Vernier current adJustment for t e secon ar wind- 1ng19 and the relay secondary windings 13. v .efer'rmg to Fig. 6, the operation charac` terlstlcs of a relay incorporating the present invention are plotted as a time-load curve. As indicated by curve 1, the torque compensator of the present invention provides a flat-curve characteristic which may be altered to that shown by curves 2 and 3. respectively b permitting the torque compensator to be linked by more or less lines of the leakage flux of the main' energizing winding 12.

It is' quite obvious that the polarity of t-he secondary winding 19 of the torque compensator may be chan ed to permit the linkage of the leakage ux of the energizing winding 12 tov add to the ilux produced by the prima winding 18 of the torque compensator. n this manner, the relay may be provided with any desired inverse-time characteristic.

Fig. 5 represents a modified means of chan ing the torque exerted on the armature mem r of a relay. This scheme comprises, in effect, the shunting of part of the magnetic flux ordinarily allowed to react with the armature member.

current-flow in the main energizing A relay is diagrammatically shown as comprising a magnetic core 31 and amain energizing winding 32. The ma netic circuit 31 of the relay is provided wit a phasesplitting means or short-circuitinv turn 33 which cooperates with the magnetic flux set up in the main energizing winding 32 to effect a rotating flux on an armature disc 34. The armature disc 34 is mounted upon a spindle 36 which is sup orted by means ofy upper and lower jewel respectively.

The shuntngmeans, which is provided for decreasing the effect of the relay magnetic flux, is represented as an iron member 39 which is adapted to be attracted toward the poles of the core member 31, against the action of a spring 41, whenever the current passing through the main energizing winding 32 exceeds a redetermined value. It may be seen, there ore, that the iron member 39 provides a magnetic shuntfor some of arings 37 and 38,

-the magnetic flux in the core member 31, and

lli

stant tor ue on a relay armature would he to provi e the usual main electromagnet which saturates at high currents, and a sms auxiliary electromagnet having a winding serially connectedvto the energizing winding of the'main electromagnet and which does not saturate at high current values. 'lhis auxiliary electromagnet would provide a torque acting in the opposite direction to the torque supplied bv the main electro-magnet. lil-this manner, the time-load curve may he adjusted 'to conform to a dat characteristic, as indicated in curve l, Fig. 6.

As referred to hereinbeiore, the present invention may be applied toy any known relay structure in order to provide for predetermined torque conditions acting upon the relay armature to secure any time-load characteristic desired. Because of the novel fee,-

' ture oi permitting the 'torque compensator tol assume a dual role in providing a means for attening the time-load-curve characteristie of a relay, and in permitting diderent winding oi such a relay to linh wi 'constitutes a substantial improvement in I i a winding electrically associated with said values of lealxage dux of the main eneriaing the torque compensator, the present invention the relay art. ln view ofthe novel and useful tentures included in the present invention, no limitations should he imposed thereon other than such as may be im osed hy vthe prior art und by the appended c aims.

l claim as my'invention:

i. ln an induction-disc-type electro-responsive means, energizing means therefor including primary and secondary windings, means movably associated with said primary winding for edecting a proportionate degree of energization o said secondary winding in acordance with the magnitude oi ,flux linkage between said primary winding and said associated means.

2. rllorque-compensating means ,for an electro-responsive device having an armature, primary and seconder windings for providing a torque for sai armature, includin winding means movahly and magnetical y associated with said primary wind- 3. ln an electro-responsive means, an ares mature, primary and secondary windings for neueres etecting a rotating torque for said armature, and torque-compensating mean movahly and magnetically essocieted with seid rimery winding, including one winding electrically associated with said primary winding and another winding electrically associated with said secondary winding.

4:., Means for predetermining the opereting characteristic of an electro-responsive device having a rotatable armature and primary andsecondury windings for producindg e torque acting upon said. armature, inclu ing a plural-winding means having one windg electrically associated with said primary winding and another winding. electrically associated with said secondary winding, said plural-winding means Ming movahly positioned with respect to'said primary winding and adapted to he linked hy the leakage dun thereof.

5. An adjustable torque compensator for an electro-responsive device having an armature and torque producing windin associated therewith, including transdrming means electrically associated with said torque-producing windings, and means for movahly positioning said transforming means with respect to one of said windings to permit a predetermined dux linkage of said transformer means and the leakage dux oi said winding.

6. ln an electro-responsive device having an armature, primary and secondary windings associated therewith for producing a torque on said armature, means for predetermining the torque exerted on said armature hy said winding, includin means movably positioned with respect to t e leakage dus of said primary winding, said means including primary and secondary windings.

ln an electro-responsive device having an armature, primary and secondary torqueproducing windings associated therewith,

means for predetermining the. time-operation characteristics of said device including inductively related windings movahly positioned withl respect to said primary winding and adapted to be linked hy leakage. dux of said primary winding, said inductively related winding being electrically associated with said primary and secondary windings .and adapted to re ulate the magnitude 'of current dow in sai secondary winding. 8. ln an induction-disc-type velectro-responsive means including a main energizing means, winding means movably associated therewith and arranged to be linked by leakage dun thereof for predetermining the time element of operation of said electro-responsive means. y l

9. ln an electro-responsive device, an armature, torque producing windings associated therewith including s. main energizing winding and secondary winding, and means for predetermining the magnitude of current flow in said secondary winding including inductive means electrically associated with said windings and movable with respect to said 11min enex'fvzin winding for predetermining the effective ux linkage 0f said inductive means with said main energizin winding.

n testimony whereof, I have hereunto subscribed my name this 15th day of October,

JOHN V. BREISKY. 

